1. Field
The present disclosure relates to an optical module, a method of making the same and an electronic device including the same.
2. Description of the Related Art
An optical module may, for example, be used as a proximity sensor of a mobile electronic device, such as a smartphone, and can be used to sense objects in the proximity of the optical module. The optical module may have a light-emitting component and an optical sensor, wherein the optical sensor can receive or sense light emitted by the light-emitting component and reflected by a nearby object (e.g., a human face surface of a user of a smartphone), to sense proximity of the nearby object, thereby facilitating the mobile electronic devices to carry out an automatic screen turn-off action.
When optical components such as a light-emitting component and an optical sensor are fixed to a substrate of the optical module, it is likely that alignment is not relatively accurate. For example, when a die bonder fixes a die onto the substrate, it is likely to produce a shift (placement error) of approximately 10 micrometers (μm) or more. The shift can cause the light-emitting component and the optical sensor to be misaligned on a designed optical path, thereby affecting operation performance of the optical module.
In addition, a transparent packaging material can be used to clad the light-emitting component and the optical sensor to achieve a protection effect, and a transparent packaging material in a predetermined shape can be further formed above the light-emitting component and/or the optical sensor to form a lens, to achieve a light-gathering or light guiding effect. However, a molding technology that may be used to perform a process of forming a lens from a transparent packaging material may cause errors in a size of a mold cavity or errors in the size and position of the lens, caused by accumulation of mechanical errors of mold alignment. Such errors can affect operation of the optical module, such as low coaxiality between a lens center and a lighting source, which can directly cause reduction of luminous efficiency. Additionally, a cost of using a transparent packaging material to form a lens and a mold increases when there is a diversity of specifications such as size or custom requirements of the optical module.
Further, positioning holes on the substrate of the optical module have certain manufacturing tolerances, such that if a housing that isolates the light-emitting component and the optical sensor is fixed onto the substrate, a corresponding error will be produced, which may cause reduction of predetermined cross talk prevention capability of the housing.